One thing that I wish Spotify (or any offline player, really, but we'll start with Spotify) had was the ability to track when there's a side break in an album for albums released and designed for listening on vinyl.

For an example of why this would be useful, listen to Abbey Road by the Beatles and notice the jarring transition from "I Want You (She's So Heavy)" and "Here Comes the Sun" on, say, Spotify.

Then listen to it on vinyl - you'll notice you have to get up, flip the record, and then start it again between the two songs which gives a natural break without the instant tonal shift instead of a smash cut from one song to the other.

This would play out the same on cassette tapes, flipping the side of the tape between the two.

It's only with the advent of CDs and streaming music that this has become a problem. It's not the end of the world, but I'm kind of baffled that there's not a way to automatically do this using some sort of metadata tags and intelligence in the player.